Late-onset traumatic laser in situ keratomileusis (LASIK) flap dehiscence.

PURPOSE: To report a case of laser in situ keratomileusis (LASIK) flap dehiscence following focal trauma six months after uneventful refractive surgery. METHODS: Case report. A 37 year old man was seen one day after a tree branch snapped tangentially against his left cornea causing a dehiscence of his LASIK flap. RESULTS: The flap was repositioned after treating the exposed flap stroma with a 50:50 mixture of distilled water and balanced salt solution. The patient regained 20/20 uncorrected visual acuity. CONCLUSIONS: Patients should be informed about the potential for traumatic flap dehiscence following LASIK surgery and advised to wear eye protection when appropriate. Due to minimal wound healing except at the edges of the flap, corneal flap dehiscence may occur months or years after uneventful LASIK.

Simplified technique for acrylic intraocular lens explantation.

A simplified technique to explant an acrylic (AcrySof) intraocular lens through the original scleral frown incision is presented. After the haptics have been separately removed from the optic, the optic is grasped by a lens holder forcep and wiggled through the incision site. No wound enlargement is necessary. The limited intracameral manipulations minimize any potential damage to the posterior capsule or corneal endothelium.

Delayed onset keratectasia following laser in situ keratomileusis.

We present a case of unilateral iatrogenic keratectasia developing 10 months after bilateral laser in situ keratomileusis (LASIK) involving enhancement surgery using a broad-beam excimer laser (Summit Apex) to treat 6.6 diopters (D) of myopia. The ectasia progressed rapidly over the subsequent 12 months. The surgeon did not measure preoperative pachymetry, but preoperative topography and corneal measurements did not reveal underlying keratoconus or forme fruste keratoconus. Corneal transplantation was required for final visual rehabilitation. Light microscopy of the button revealed no underlying inflammation, which suggests biomechanical corneal weakening as the cause of the ectasia. Scanning electron microscopy showed the dramatic thinning seen clinically. latrogenic keratectasia appears to be a possible complication of LASIK.

New corneal marker for passing a 24-bite anti-torque corneal transplant single continuous suture.

The use of a single continuous-suture closure technique allows the surgeon to minimize corneal transplant astigmatism within 1 month of surgery. Passage of this suture in a precise, anti-torque pattern is difficult. A new surgical instrument has been designed to place 24 equidistant dots on both the recipient and the donor tissues after the cardinal sutures have been placed. The surgeon simply must "connect the dots" to achieve a rapid, precise anti-torque closure. The instrument is easy to use and should prove helpful to surgeons who perform the single, continuous-suture closure technique.

Irreversible bullous keratopathy after air bag trauma.

PURPOSE: We describe an unusual case of corneal decompensation following air bag trauma in a 38 year-old-female. METHODS: The patient was followed clinically for 5 months post-injury with persistent corneal edema that failed to resolve, necessitating corneal transplantation. Scanning electron microscopy (SEM) of the corneal button was performed. RESULTS: SEM revealed localized areas of complete endothelial destruction. Other areas of the endothelium had cell counts under 1,000 cells per square millimeter. CONCLUSIONS: This case corroborates animal studies demonstrating endothelial cell loss from direct air bag trauma and stresses the need to possibly redesign this safety device for maximum driver protection.

Effect of peripheral subepithelial fibrosis on corneal transplant topography.

Subepithelial fibrosis in the area of peripheral suture placement is an often overlooked phenomenon of healing following uneventful penetrating keratoplasty surgery. Three affected cornea transplant patients whose sutures had been removed were studied using videophotokeratoscopy before and after stripping of the subepithelial tissue with cellulose sponges and jeweler's forceps. All three showed relative flattening in the involved hemimeridian prior to treatment. Removal of the fibrotic tissue produced relative steepening in the same area. Overall graft astigmatism was essentially unchanged following the procedure in each patient. However, average central keratometric readings increased approximately 1 to 2 diopters in each patient, demonstrating that these peripheral changes have a direct influence on corneal power. The surface regularity index and surface asymmetry index values improved in two of the three patients and manifest spectacle visual acuity improved in each patient.

Use of demineralized bone as an osteoinductive orbital enucleation implant in the rabbit.

Implanted allogeneic demineralized bone particles (DBP) may be transformed into endochondral bone by inductive or conductive new bone formation. Using a rabbit model, enucleation or evisceration was performed, and DBP was implanted into the socket. Histology confirmed endochondral bone formation in both groups. A morphologic difference existed between enucleation and evisceration: compact bone was produced following evisceration, and cancellous bony spheres were formed following enucleation. Serial quantitative computed tomography (qCT) was performed to monitor mineral density and proved to be an ideal technique to monitor bone mineralization noninvasively in the postoperative orbit. Bone mineral density (BMD, mg/ml) increased approximately 300% in DBP implanted orbits when compared to controls at 6 weeks. The ideal mass/volume ratio of DBP to socket volume was 400 mg/ml. The rapidly formed bone is well vascularized and creates a stable integrated orbital implant, following enucleation and evisceration surgery. DBP implantation into the central orbit results in inductive bone formation with interesting potential in socket and orbit reconstruction.

HLA-DR alleles and sterile ulcerative keratitis.

Human leukocyte antigen-DR typing was performed on 18 unrelated white patients with sterile ulcerative keratitis (SUK) to determine whether these patients share common immunogenetic susceptibility genes. There was no statistically significant increase in any DR allele among the entire group of SUK patients. There was a trend in the frequency of DR1 in the rheumatoid arthritis (RA) patients (5 of 8, 63%) versus the non-RA patients (1 of 10, 10%), which was not statistically significant, possibly due to the small number of patients in the study. Screening patients with RA without known SUK from our RA register revealed one DR1-positive patient with an inactive peripheral marginal melt. These findings suggest a possible relationship between DR1 and RA sterile corneal melting, which will need to be confirmed with a larger study.

Intraocular lens implantation after penetrating keratoplasty. Improved unaided visual acuity, astigmatism, and safety in patients with combined corneal disease and cataract.

Twenty-two eyes with combined corneal disease and cataract were followed prospectively after nonsimultaneous intraocular lens (IOL) placement after penetrating keratoplasty; the majority had a penetrating keratoplasty and planned extracapsular cataract extraction (ECCE) followed later by the placement of an IOL. The mean follow-up after IOL placement was 25 months (range, 3-55 months). No graft failures occurred after secondary surgery. All graft sutures were removed in 86% (19/22) of eyes before IOL surgery. Ninety-five percent (21/22) of the eyes achieved refractive errors within 2 diopters (D) of the desired result. Corneal astigmatism decreased from 4.88 to 2.92 D after secondary surgery and wound revision. Unaided visual acuity was 20/40 or better in 68% (15/22) and 20/100 or better in 91% (20/22) of the eyes. The advantages of excellent unaided visual acuity, reduced astigmatism, and lack of anisometropia and graft failure outweigh the disadvantage of some delay in final visual rehabilitation (11 months) and increased secondary capsulotomy rate (85%) in this series with two separate surgeries compared with previously reported triple procedure results.

Successful treatment of recurrent corneal erosion with Nd:YAG anterior stromal puncture.

I used a new technique to create anterior corneal stromal punctures for the treatment of traumatic recurrent corneal erosions that had not responded to conventional therapy. Three patients with such erosions within the visual axis were successfully treated by using multiple applications of the Nd: YAG laser set at energy levels between 1.8 and 2.2 mJ. One of these patients had previous stromal puncture with a bent 25-gauge needle. The erosions of all patients healed without complications and have remained symptom-free for four to six months. Compared with needle puncture, the laser punctures were more reproducible, shallow, and translucent.

Anterior stromal puncture with the Nd:YAG laser.

A simple and consistent puncture of the anterior stroma was created with the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser in a rabbit model. Varying energy levels were tested, and settings at 2.0 mJ produced well-formed anterior stromal breaks. The laser shock wave disrupted Descemet's membrane in only 1 of 50 animals. The wound healed normally in vivo over a 3-month period. Compared to needle puncture, the laser puncture created less stromal scarring. Initial human studies also showed that energy levels from 1.5-2.5 mJ were sufficient to create local breaks in Bowman's layer. Further human studies will be needed to determine if Nd:YAG laser puncture offers any advantages over current techniques for stromal puncture in the treatment of traumatic recurrent corneal erosions.

Limbal wedge resection at the time of intraocular lens surgery for reducing postkeratoplasty astigmatism.

Thirteen limbal wedge resections performed to reduce postkeratoplasty astigmatism in patients undergoing secondary intraocular lens placement were reviewed. Eleven of the 13 procedures reduced preoperative astigmatism 3.12 diopters (+/- 1.77 D; range, 0.50 D to 6.25 D). The average follow-up time was 17 months (range, 4 to 36 months). The average flat/steep ratio was 1.19 (+/- 0.96), indicating approximately equal degrees of corneal flattening and steepening. Average central corneal keratometric values steepened 0.47 D, with a range of 0.56 D of flattening to 2.41 D of steepening. Keratometric values were stable by 4 months in most patients. All patients except one with amblyopia had a corrected visual acuity of 20/60 or better. A dellen formation developed in one case, but it caused no permanent negative visual complications. As generally found in previous studies, each 0.1-mm wedge-width resected induced 1 D of astigmatic correction. Limbal wedge resection in conjunction with intraocular lens implantation can safely and effectively reduce astigmatism following penetrating keratoplasty.

Delayed sterile keratitis following radial keratotomy requiring corneal transplantation for visual rehabilitation.

Delayed keratitis is an unusual complication of radial keratotomy surgery. A case of documented sterile keratitis involving four adjacent nasal incisions occurred 34 months following a 16-incision radial keratotomy procedure. Multiple cultures and biopsies failed to show a pathogen. The keratitis was confined to the incisional area without involvement of the intervening stroma. A penetrating keratoplasty was necessary to restore useful vision. Clinical and pathological studies documented delayed corneal wound healing.

Cicatricial conjunctivitis in sarcoidosis: recognition and treatment.

A 30-year-old black woman with biopsy-proven ocular sarcoidosis had progressive conjunctival cicatrization of the inferior fornix over a one-year period. Treatment with corticosteroid injections into the inferior cul-de-sac partially reversed the scarring process.

Transplant of oral mucosal epithelium to rabbit ocular surface wounds in vivo.

Sheets of epithelium freed of underlying connective tissue and basal lamina with dispase II were obtained from explants of rabbit oral mucosa. Epithelial sheets were then sutured onto abraded (basement membrane intact) or keratectomized corneal-limbal zones or abraded central corneas of anesthetized rabbits. To develop the procedure, allografts to abraded (N = 13) and keratectomized wounds (N = 3) on the corneal-limbal zone were done. All allografts were retained on the wound bed until the experiment was terminated or rejection occurred. Prior to rejection, eyes were uninflamed and quiet. Allografts on central avascular corneal wounds (N = 8) were not maintained. Autografts (N = 4) sutured to corneal-limbal abrasion wounds were maintained until animals were killed at the end of the experiment, 22, 26, 60, and 120 days after transplant. Eyes were uninflamed and quiet. A fine vascular bed developed under both allografts and autografts in the peripheral cornea. Grafts maintained some histologic characteristics of oral mucosal epithelium, even after four months. These data indicate that it is feasible to transplant oral mucosal epithelium to corneal-limbal ocular surface wounds and that the grafts will be maintained. Such transplants are, however, not maintained over central, avascular corneal regions.